The invention relates to services conveyed to subscribers via a mobile communication system, and particularly to services-on-demand for which the subscriber is charged.
In connection with fixed networks, various broadcast services have been implemented to be used by a user when desired, such as a video-on-demand, for example. The subscriber generally pays for such a service according to use. Below, such services will be called services-on-demand. In a fixed network, a subscription service can be readily broadcast and subscribers for these services can be readily charged since the service-on-demand is provided at a particular stationary location of use in accordance with an agreement.
The problem presented by the arrangement described above is, however, that it cannot be implemented as such in mobile communication systems wherein the subscriber can freely move in the system area. Prior art mobile communication systems have services liable to charges available but the services are based on point-to-point transmissions, which burden the network. Broadcasts implemented in mobile communication systems are cell-specific cell broadcasts containing information intended for all mobile stations located in the cell. For example the pan-European GSM (Global System for Mobile Communication) system defines, in addition to cell broadcast, transmission modes of broadcast nature, such as point-to-multipoint transmission wherein a message is transmitted to all subscribers or predetermined subscriber groups in an area and at a moment determined by the message transmitter. In ‘multicast’, a special form of the point-to-multipoint transmission, a message is transmitted to the subscribers located at a particular moment in a particular geographical area. The transmitted message includes a group identifier, and only those subscribers that belong to the group receive the message. These transmission modes are not, however, suitable for implementing services-on-demand since the reception moment of the message is determined by the transmitter, who is also charged.